Turning tool applicable to remove refractory screws



June. 3, 1930.- F. R. RosAN.

TURNING TOOL -APPLICABLE TO REMO'VE REFRAGTORY SCREWS Filed Aug. 8, 1929 ardl'nund Ffober' Rosan Patented June 3, 1930 UNITEDA STATES FERDINAND ROBERT ROSAN, OF BENDIGO, AUSTRALIA TURNING Toor, APPLICABLE To nEMovE REFRACTORY scnnws Application mea August s, 1929, serial No. 384,392, andinAusti-ana' May e', 1929.

An object of this invention is to provide a tool usableto loosen inserted screws which resist ordinary efforts to withdraw them. My tool is usable to rotate screws which are cor- '5 roded or have damaged or broken heads. It

can also be applied for inserting and tightening screws and for various other purposes involving rotation by the application of considerable force.

Another object of the inventionis to produce, simultaneously, a triple effect; (l) pressure in the desired direction, as downward; (2) shock or jar to loosen the impacted screw or article; and (3) application of torsional stress to produce rotation.

This tool includes a member which causes the triple effect aforesaid, by reason of the shape of said member or the striker thereof. The preferred form of tool is herein der scribed with reference to the drawings. The

said member has a bit, or screw engaging element, a stem usable as a handle, and a head havinginclined surfaces, on which suitable blows have the effect of transmitting to the bit, and so to the refractory screw or object engaged thereby, the said triple effect.

In my preferred arrangement the tool head is bifurcated, and adapted to be struck by a hammer having a suitable striking edge, wedge shaped being suitable.

One suitable form of the bit is that of an ordinary screwdriver. I find it however an advantage to provide the bit with cutting edges, when the screw needs a better slot. These edges as a result of the heavy blows the head receives, accentuate the screw slot, or cut a fresh one if the original is absent, to ensure grip for turning purposes.

In the drawings herewith in which the scales vary, I illustrate embodiments of my invention, but details shown can be modified,

while retaining characteristics hereinafter impact by a striker, whereby to twist the tool in one ofthe directions indicated by arrows. Figure 3 shows a tool with modified horns.

Figure 4 is a planof-the head in Figure 3, a dottedl line indicating 'the plane of impact. u

Figure 5 shows a toolwith its pointorbit shaped to suit its application to a broken screw requiring extraction, shown below it.

Figure 6 is a perspective view of a tool bit, on a larger scale.

The tool and its bit may be one piece; or,

as shown in Figures land 3 a removable bit is located in a socket. The stem of the tool can be held by hand to steady` the tool duri-ngV the striking action.v

f In experiments I have found that a striker can be used in engagement with means to guide itin thedirection requiredfor impact; it could be of sleeve form, engaging a suitable stem, or it could slide inside guides, but the free striker shown in Figure lis simple and elfective. i

The tool head II has V shaped or inclined linel B1, or B2, iny Figure 2, according to whether the screw 1s to be removed-or to bemore `tightly inserted. To remove the screw the blows are on line B1 rotating the tool lin the direct-ion of arrows'Al.' Totighten a screw the blows are on line B2, causing rota'- tion in direction of arrows A2. Whenthe striker meets the sides of the limbs it urges leach limb clockwiseor contra-,clockwise as the case may be. y

)For rotation in 'one direction only, it is practicable yto provide limbs which diverge helically or sideways as in Figures 3 and 4, to receive blows'on line B3, 'causing rotation in direction of arrows A3.

f The llimbs are shown tapered at L4 Figure 1, but limbs of equal thickness throughout will serve.v y` .f

Thefstriking tool shown inFigure lis effective. It has a handle W,1a wedge y.shaped edge W1, and it can have a hammer head W2, for other uses.

In the stem L3 is a socket for a bit T, having any suitable point T1. In order to ensure a rm grip on the head S of a screw S1, or the like, the bit edge is conveniently made with oppositely bevelled faces T2, T3, having between them a recess as T5, or meeting at T4 without a recess. Screws having well defined slots can be engaged by the bitreadily and are not damaged thereby, but damaged or corroded screws may need to be prepared for the bit as by punching with a cold chisel to form a suficient indentation for preliminary grip.

To extract a brokenl screw S2, the procedure found effective is to drill a hole S3 in it and to use a bit which has a wedge shaped end T6. and faces T7, by which to grip in a recess.

l/Vhen the tool point is set in position ready to be struck, it may be given a few preliminary blows in the fork on line B1 to ensure engagement, after which it is to be struck heavily in the correct plane described, to obtain the said threefold effect.

In the claims the word screw is used to denote any object, to the rotation of which force is to be applied, to extract or loosen said object, or, if required, cause it to hold more tightly.

I claim z l. A tool having a point to engage a screw and a head having outwardly tapered fingers forming a downwardly directed apex adapted to be struck by an implement to impart pressure, sudden shock and torsional stress to said screw.

2. A tool having a point to engage a screw and a V-shaped head whereby, when said head is struck by an implement in the direction of the axis of the tool, pressure, sudden shock and torsional stress are imparted to said screw.

3. A tool having a point to engage a screw and a head having outwardly tapered helical fingers forming a downwardly directed apex adapted to be struck by an implement to impart pressure, sudden shock and torsional stress to said screw.

4. A tool having a point to engage a screw and a V-shaped head with helical arms, whereby, when said head is struck by an implement in the direct-ion of the axis of the tool, pressure, sudden shock and torsional stress are imparted to said screw. Y

5. A tool having oppositely disposed cutting edges atits point to engage a screw and l sudden shock and torsional stress to a screw driver.

v In witness whereof I have hereunto signed my name to this specification at Melbourne in the State of Victoria, in Australia, this ninth day of July, 1929.

FERDINAND ROBERT ROSAN.

a V-shaped head with helical arms, whereby,1

when'said head is struck by an implement in the direction of the axis of the tool, pressure, sudden shock and torsional stress are imparted to said screw.

6. A tool having a head provided with outwardly tapered fingers forming` a downwardly directed apex adapted to impart pressure, 

